Image generation using surface-based neural synthesis

ABSTRACT

Aspects of the present disclosure involve a system and a method for performing operations comprising: receiving a two-dimensional continuous surface representation of a three-dimensional object, the continuous surface comprising a plurality of landmark locations; determining a first set of soft membership functions based on a relative location of points in the two-dimensional continuous surface representation and the landmark locations; receiving a two-dimensional input image, the input image comprising an image of the object; extracting a plurality of features from the input image using a feature recognition model; generating an encoded. feature representation of the extracted features using the first set of soft membership functions; generating a dense feature representation of the extracted features from the encoded representation using a second set of soft membership functions; and processing the second set of soft membership functions and dense feature representation using a neural image decoder model to generate an output image.

CLAIM FOR PRIORITY

This present application is a continuation of U.S. patent applicationSer. No. 16/949,773, filed Nov. 13, 2020, which claims the benefit ofpriority to U.S. Provisional Application Ser. No. 62/936,328, filed.Nov. 15, 2019, each of which are herein incorporated by reference intheir entireties.

TECHNICAL FIELD

The present disclosure relates to the use of continuous surface-levelparametrizations of objects to synthesize images.

BACKGROUND

Modern day user devices provide messaging applications that allow usersto exchange messages with one another. Such messaging applications haverecently started incorporating graphics in such communications. Thegraphics can include avatars or cartoons that mimic user actions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. To easily identifythe discussion of any particular element or act, the most significantdigit or digits in a reference number refer to the figure number inwhich that element is first introduced. Some nonlimiting examples areillustrated in the figures of the accompanying drawings in which:

FIG. 1 is a diagrammatic representation of a networked environment inwhich the present disclosure may be deployed, in accordance with someexamples.

FIG. 2 is a diagrammatic representation of a messaging system, inaccordance with some examples, that has both client-side and server-sidefunctionality.

FIG. 3 is a diagrammatic representation of a data structure asmaintained in a database, in accordance with sonic examples.

FIG. 4 is a diagrammatic representation of a message, in accordance withsome examples.

FIGS. 5 and 6 are diagrammatic representations of the operationsperformed by a pose generation system, in accordance with some examples.

FIG. 7 is a diagrammatic representation of the diffusion and attentionlayer, in accordance with some examples.

FIG. 8 is a diagrammatic representation of the position and featurestatistics modeling, in accordance with sonic examples.

FIG. 9 presents diagrammatic representations of graphical userinterfaces, in accordance with some examples.

FIGS. 10A and 10B are flowcharts illustrating example operations of themessaging application server, according to examples.

FIG. 11 is a diagrammatic representation of a machine in the form of acomputer system within which a set of instructions may be executed forcausing the machine to perform any one or more of the methodologiesdiscussed herein, in accordance with some examples.

FIG. 12 is a block diagram showing a software architecture within whichexamples may be implemented.

DETAILED DESCRIPTION

The description that follows includes systems, methods, techniques,instruction sequences, and computing machine program products thatembody illustrative examples of the disclosure. In the followingdescription, for the purposes of explanation, numerous specific detailsare set forth in order to provide an understanding of various examples.It will be evident, however, to those skilled in the art, that examplesmay be practiced without these specific details, In general, well-knowninstruction instances, protocols, structures, and techniques are notnecessarily shown in detail.

Neural image synthesis can be controlled by conditioning the operationof a network on a given signal, which can he a categorical label, text,or layout constraints indicated by another image. Typical systems learna fully disentangled image synthesis by combining 3D and 2D datasets orunstructured 2D image sets, allowing one to explicitly control camera,shape, and illumination parameters. When focusing on humans, theconditioning signal can include human keypoints, semantic parts, orDensePose-level information. Typically, this is done by encoding thisinformation as additional input channels which are concatenated with theRGB image and fed to a CNN, or by using pose information in conjunctionwith a Spatial Transformer that densely warps RGB values or neuronactivations.

The disclosed examples improve the accuracy of neural synthesis modelsand make such models more controllable by exploiting continuous,surface-level parameterizations of object category shape, focusing inparticular on humans. Specifically, according to the disclosed examples,a charted, UV coordinate-based representation of humans is used toimprove image synthesis in terms of both controllability and realism.The charting is integrated in two complementary approaches to imagesynthesis: parametric generative models such as principal componentanalysis (PCA) or AutoEncoders, where an explicit image encodingdetermines image synthesis; and descriptive models, where an image issynthesized through moment matching so as to be statisticallyindistinguishable from a target signal. As a parametric model, thedisclosed examples use a semantic conditioning signal to modulate adecoder's behavior through Adaptive Instance Normalization. As adescriptive model a Universal Transfer method is used which applies thecolorization-and-whitening (CWT) transform to match the Gram Matrices ofa content and a style signal.

Specifically, a 2D input image is received and features of the inputimage are obtained. The features are pooled and assigned to differentchannels depending on the region-specific appearance information, suchas hair color and style around faces or show type around feet. Thisinformation is compressed and a membership-weighted estimate of meansand variance is applied per channel. As an example, every row of amatrix corresponds to one human joint. To construct this matrix, weobtain features defined for the image and for every joint, the disclosedexamples emphasized those features that are likely to contain the jointinto the corresponding matrix row. A target image, such as an imagedepicting a different pose is received. The target image is processed byobtaining pixel values of different regions of the image based on adense pose function. As an example, a region of the target imagecorresponding to a shoulder landmark is analyzed to obtain a set ofpixel values associated with that region of the target image. Thesepixel values are assigned as target soft intrinsic distances. These softintrinsic distances are concatenated with the pooled features of theinput image and decoded to generate a decoded image in which the inputimage appears with features of the target image. For example, the inputimage depicting a person in one pose is decoded to generate an outputimage in which the person is depicted in another pose.

According to a first aspect, this disclosure describes a computerimplemented method of neural image synthesis, the method comprising:receiving a two-dimensional continuous surface representation of athree-dimensional object, the continuous surface comprising a pluralityof landmark locations; determining a first set of soft membershipfunctions based on relative location of points in the two-dimensionalcontinuous surface representation and the landmark locations; receivinga two-dimensional input image, the input image comprising an object ofthe same type as the three-dimensional object; extracting a plurality offeatures from the input image using a feature recognition model;generating an encoded feature representation of the extracted featuresusing the first set of soft membership functions; generating a densefeature representation of the extracted features from the encodedrepresentation using a second set of soft membership functions; andprocessing the second set of soft membership functions and dense featurerepresentation using a neural image decoder model to generate an outputimage.

A two-dimensional continuous surface representation of athree-dimensional object comprises a map of the surface of athree-dimensional object onto a two-dimensional planar region. It mayalso be referred to as a “charting”. The representation is continuous inthe sense that the two-dimensional representation of the object is notdisjoint, i.e. different elements of the object are not split up intoseparate two-dimensional representations. In some examples, such amapping is obtained by effectively “unwrapping” and “flattening” thethree-dimensional surface into two dimensions. This unwrapping processmay not fully fill an area used for the two-dimensional continuoussurface representation—the remaining portion of the area may be referredto as the “background”. The two-dimensional continuous surfacerepresentation may itself be in the form of an image. An example of sucha two-dimensional continuous surface representation is a UV map that maybe generated from a three-dimensional object using UV unwrappingtechniques. Other equivalent representations may alternatively be used.

Determining the first set of soft membership functions may comprise:determining distances between a plurality of points in thetwo-dimensional continuous surface representation and the landmarklocations; and assigning each point in the plurality of points to alandmark based on the determined distances.

The sets of soft membership functions are functions that associatepoints (e.g. pixels) in the two-dimensional continuous surfacerepresentation to one or more of the landmarks. In effect, the softmembership functions correspond to regions that roughly positionlocations on the object. A background membership function may also beincluded in the set that assigns points in the two-dimensionalcontinuous surface representation that are determined not to be on theobject to a background label. In some examples, the soft featurerepresentation assigns each point to its nearest landmark. In otherexamples, the soft feature representation assigns a set of weights toeach point, each weight associated with a different landmark and basedon the distance to said landmark, e.g. the greater the distance, thesmaller the weight.

Determining the landmark locations may comprise using a landmarkrecognition model.

The landmarks (also referred to as “object landmarks”may) representkeypoints of the object. The landmarks may be specific to an objecttype. For example, in examples where the object is a human body, thelandmarks may be keypoints of the human body, such as joints, facialfeatures etc. The object landmarks may be labelled/located manually, ormay be labelled/located using a landmark recognition/location model (forexample, a neural network trained to locate landmarks in thetwo-dimensional continuous surface representations of particular objecttypes).

The neural image decoder model may comprise a convolutional neuralnetwork conditioned on the two-dimensional continuous surfacerepresentation.

Generating an encoded feature representation of the extracted featuresusing the first set of soft membership functions comprises performing amembership-weighted estimate of a mean and variance for each channel ofthe extracted features. The encoded representation may comprise anestimate of the mean and variance for each channel of the extractedfeatures, i.e. feature statistics in the vicinity of the landmarks.

Generating a dense feature representation of the extracted features fromthe encoded representation using a second set of soft membershipfunctions may comprise applying a dual operation to themembership-weighted estimate of a mean and variance for each channel ofthe extracted features.

The dense feature representation may also be referred to as a “featurefield” or “pixelate representation”. Soft feature unpooling may be usedto generate the dense feature representation, i.e. an inverse/dualoperation to soft feature pooling. The unpooling effectively spreadsfeatures in the encoded feature representation over the correspondingareas of an image. In other word, it broadcasts the encoding back intoan image domain.

In some examples, the first set of soft membership functions and thesecond set of soft membership functions are the same. The method mayfurther comprise: generating a three-dimensional model/representation ofthe three-dimensional object from the input image; and generating thetwo-dimensional continuous surface representation from thethree-dimensional model/representation. The method may further comprisemodifying values in the encoded representation prior to generating thedense feature representation.

Re-using the first set of soft membership functions to generate a densefeature representation that allows shape and appearance information inan input image to be disentangled, providing a means for independentcontrol/variation of shape and appearance during image generation.

A three-dimensional model/representation, such as a DensePoserepresentation, may be determined from the input image, and then used togenerate the two-dimensional continuous surface representation, forexample using UV unwrapping. The two-dimensional continuous surfacerepresentation then corresponds to the input image.

The two-dimensional continuous surface representation of athree-dimensional object may be generated from the input image. Themethod may further comprise: receiving a further two-dimensional inputimage, the further input image comprising a further object of the sametype as the three-dimensional object; generating a furthertwo-dimensional continuous surface representation of saidthree-dimensional object from the further two-dimensional input image,the further continuous surface comprising the plurality of landmarklocations; and determining the second set of soft membership functionsbased on relative locations of points in the further two-dimensionalcontinuous surface representation and the landmark locations.

Determining the first set of soft membership functions from the inputimage and the second set of soft membership functions from a differentinput image allows pose/style information to be transferred from oneimage to the other. For example, the (first) input image may comprise animage of an object (e.g. a human) in a first pose, and be used todetermine the first set of soft membership functions. The second inputimage may comprise an image of an object (e.g. human) in a second pose,and be used to determine the second set of soft membership functions.Extracting features from the first image and generating the encodedrepresentation of them with the first set of soft membership functionsassociates features of the first image with the object landmarks.Unpooling the encoded representation of the features of the first imagewith the second set of soft membership functions to generate the denserepresentation effectively transfers features of the first image onto animage with the pose of the second image.

Generating the further two-dimensional continuous surface representationfrom the further (i.e. second) image may be performed in the same way asgenerating the two-dimensional continuous surface representation fromthe input (i.e. first) image.

The input image may comprise an image of the object in a first pose andthe further input image may comprise an image of the further object in asecond pose. The second image may comprise portions corresponding tounseen portions of the first image. Generating the two-dimensionalcontinuous surface representation from the input image may comprisegenerating portions of the two-dimensional continuous surfacerepresentation corresponding to the unseen portions of the first imagefrom the encoded representation using a learned attention mechanism. Thelearned attention mechanism may be based on the first set of softmembership functions.

When the input (i.e. first) image and further (i.e. second) image showan object in a different pose, there may be regions of the second imagethat are not present in the first image, and therefore cannot bedirectly transferred from the first image. These regions can beinterpolated from the first image using a learned attention mechanism.The observed features of the first image (i.e. the extracted features)can be diffused across the landmarks to generate a diffuse set offeatures using a learned model, such as a matrix or a neural networkwith learned weights, parameters and/or components. An attentionmechanism is used to generate a refined set of features by combing thediffuse set of features and the observed set of features to prevent thediffuse set of features from overriding the observed features.

According to another aspect, this disclosure describes a computerimplemented method of style transfer, the method comprising: determininga set of content features from a source image using an encoder neuralnetwork; determining a set of style features from a style image usingthe encoder neural network; determining position dependent contentfeatures using joint statistics of position and content features inregions of the source image; determining position dependent stylefeatures using joint statistics of position and style features inregions of the style image; generating a set of transformed contentfeatures from the set of position dependent content features based onthe joint statistics of position and content features; generating a setof transformed style features from the set of transformed contentfeatures based on the joint statistics of position and style features;and generating an output image from the transformed set of stylefeatures and the transformed set of content features using a decoderneural network.

The method may provide an enhancement to other descriptive methods, suchas the whitening and color transformation, by taking into accountnon-stationary patterns in the input images using the position dependentstyle and content features.

The content features and style features may be determined from thesource and style images respectively using a feature recognition neuralnetwork. An example of such a network is the VGG network, though otherfeature recognition networks may alternatively be used. The decoderneural network may be an neural network trained to reproduce images fromfeature maps produced by the feature recognition neural network.Together, the feature recognition neural network and the decoder neuralnetwork may form an autoencoder system.

The style image and/or source image comprises a continuoustwo-dimensional representation of a three-dimensional object, asdescribed above in relation to the first aspect.

The joint statistics of position and content features comprise a contentfeature mean, a content position mean and covariances between contentfeatures and content positions, and wherein determining positiondependent content features comprises determining a conditional model ofthe content features conditioned on position. The conditional model ofthe content features may comprise a position dependent content mean anda conditional content covariance. Generating the set of transformedcontent features from the set of position dependent content features maycomprise: centering the position dependent content features based on theposition dependent content mean; and applying a whitening transformationbased on the conditional content covariance.

The joint statistics of position and style features may comprise a stylefeature mean, a style position mean and covariances between stylefeatures and style positions, and wherein determining position dependentstyle features comprises determining a conditional model of the stylefeatures conditioned on position. The conditional model of the stylefeatures may comprise a position dependent style mean and a conditionalstyle covariance. Generating the set of transformed style features fromthe set of position dependent content features may comprise: adding theposition dependent content features to the position dependent stylemean; and applying a coloring transformation based on the conditionalstyle covariance.

A model, such as a multivariate Gaussian model, may be used to capturethe dependence of the extracted content/style features on continuousposition coordinates. This model may be used to replace the staticcontent/style features used in other descriptive synthesis models, suchas the whitening and color transformation. Whitening refers to thereduction of style features present in the content features. Coloringrefers to adding style features from the style image to the (whitened)content features of the source image.

The method may further comprise: mapping the source/style image to anembedding using a trained model; and determining the joint statistics ofposition and content/style features in regions of the source/style imagebased on the embedding.

Use of an embedding of the position coordinates instead of the positioncoordinates themselves can allow complex spatial dependencies to becaptured. For example, in humans it is expected that there will bemirror symmetry about the vertical axis, but not a horizontal axis.Features will therefore be more correlated in the horizontal directionthan the vertical direction. The model may be trained based on a lossfunction that penalizes distances in the vertical direction more thandistances in the horizontal direction when generating the mapping.

Networked Computing Environment

FIG. 1 is a block diagram showing an example messaging system 100 forexchanging data (e.g., messages and associated content) over a network.The messaging system 100 includes multiple instances of a client device102, each of which hosts a number of applications, including a messagingclient 104 and other external applications 109 (e.g., third-partyapplications). Each messaging client 104 is communicatively coupled toother instances of the messaging client 104 (e.g., hosted on respectiveother client devices 102), a messaging server system 108 and externalapp(s) servers 110 via a network 112 (e.g., the Internet). A messagingclient 104 can also communicate with locally-hosted third-partyapplications 109 using Applications Program Interfaces (APIs).

A messaging client 104 is able to communicate and exchange data withother messaging clients 104 and with the messaging server system 108 viathe network 112. The data exchanged between messaging clients 104, andbetween a messaging client 104 and the messaging server system 108,includes functions (e.g., commands to invoke functions) as well aspayload data (e.g., text, audio, video or other multimedia data).

The messaging server system 108 provides server-side functionality viathe network 112 to a particular messaging client 104. While certainfunctions of the messaging system 100 are described herein as beingperformed by either a messaging client 104 or by the messaging serversystem 108, the location of certain functionality either within themessaging client 104 or the messaging server system 108 may be a designchoice. For example, it may be technically preferable to initiallydeploy certain technology and functionality within the messaging serversystem 108 but to later migrate this technology and functionality to themessaging client 104 where a client device 102 has sufficient processingcapacity.

The messaging server system 108 supports various services and operationsthat are provided to the messaging client 104. Such operations includetransmitting data to, receiving data from, and processing data generatedby the messaging client 104. This data may include message content,client device information, geolocation information, media augmentationand overlays, message content persistence conditions, social networkinformation, and live event information, as examples. Data exchangeswithin the messaging system 100 are invoked and controlled throughfunctions available via user interfaces (UIs) of the messaging client104.

Turning now specifically to the messaging server system 108, anApplication Program .interface (API) server 116 is coupled to, andprovides a programmatic interface to, application servers 114. Theapplication servers 114 are communicatively coupled to a database server120, which facilitates access to a database 126 that stores dataassociated with messages processed by the application servers 114.Similarly, a web server 128 is coupled to the application servers 114,and provides web-based interfaces to the application servers 114. Tothis end, the web server 128 processes incoming network requests overthe Hypertext Transfer Protocol (HTTP) and several other relatedprotocols.

The Application Program Interface (API) server 116 receives andtransmits message data (e.g., commands and message payloads) between theclient device 102 and the application servers 114. Specifically, theApplication Program Interface (API) server 116 provides a set ofinterfaces (e.g., routines and protocols) that can be called or queriedby the messaging client 104 in order to invoke functionality of theapplication servers 114. The Application Program interface (API) server116 exposes various functions supported by the application servers 114,including account registration, login functionality, the sending ofmessages, via the application servers 114, from a particular messagingclient 104 to another messaging client 104, the sending of media files(e.g., images or video) from a messaging client 104 to a messagingserver 118, and for possible access by another messaging client 104, thesettings of a collection of media data (e.g., story), the retrieval of alist of friends of a user of a client device 102, the retrieval of suchcollections, the retrieval of messages and content, the addition anddeletion of entities (e.g., friends) to an entity graph (e.g., a socialgraph), the location of friends within a social graph, and opening anapplication event (e.g., relating to the messaging client 104).

The application servers 114 host a number of server applications andsubsystems, including for example a messaging server 118, an imageprocessing server 122, and a social network server 124. The messagingserver 118 implements a number of message processing technologies andfunctions, particularly related to the aggregation and other processingof content (e.g., textual and multimedia content) included in messagesreceived from multiple instances of the messaging client 104. As will bedescribed in further detail, the text and media content from multiplesources may be aggregated into collections of content (e.g., calledstories or galleries). These collections are then made available to themessaging client 104. Other processor- and memory-intensive processingof data may also be performed server-side by the messaging server 118,in view of the hardware requirements for such processing.

The application servers 114 also include an image processing server 122that is dedicated to performing various image processing operations,typically with respect to images or video within the payload of amessage sent from or received at the messaging server 118. Detailedfunctionality of the image processing server 122 is shown and describedin connection with FIG. 5. Image processing server 122 is used toimplement 3D body model generation operations of the 3D body modelgeneration system 230 (FIG. 2).

In one example, the image processing server 122 detects a person in aninput 2D image. The image processing server 122 also receives a targetimage of the person or another person in a different pose than theperson in the 2D image. The image processing server 122 uses the targetimage to generate an output image that depicts the person in the input2D image in the pose of the person in the target image. In some cases,the image processing server 122 uses a charted adaptive instancenormalization (CHAIN) to perform this pose transfer. Specifically,Adaptive Instance Normalization (AdaIN) modifies the statistics of eachchannel c in a feature map through a parametric function such as amulti-layer perceptron:

${{{AdaIN}\left( x_{i}^{c} \right)} = {{\gamma_{c}\frac{x_{i} - \mu_{c}}{\sigma_{c}}} + \beta_{c}}},$

where x_(i) denotes the activation at position i, μ, σ are computed bystandard Instance Normalization, and γ, β are multiplicative andadditive gain terms that are predicted by a side branch as toappropriately modify the network's behavior. AdaIN is applied tomultiple levels of a decoder and it is shown that the values of γ, β atdifferent network depths provide a natural disentanglement of structurehierarchies. The image processing server 122 according to some examplesdetermines spatially-varying instance normalization parameters γ, βmodulated by the continuous surface representation. Specifically, CHAINuses both the input image and surface-based interpretation to constructthe conditioning signal:

$\begin{matrix}{{{{ChAIN}\left( x_{i}^{c} \right)} = {{\gamma_{c_{i}}\frac{x_{i} - \mu_{c}}{\sigma_{c}}} + \beta_{c_{i}}}},{\gamma_{c_{i}} = {{MLP}\left( {I,{UV}} \right)}_{i}}} & \end{matrix}$

The conditioning signal is designed to disentangle shape and appearance.This allows the image processing server 122 to in a second stagesynthesize the pose of a person with the clothes of another, or easilyperform appearance inpainting. The conditioning signal is constructed byfirst eliciting localized shape and appearance descriptors, and thenfusing them in a dense conditioning signal that is processed by a CNNthat regresses c_(i), b_(i) per channel. Training of the CHAIN systemimplemented by the image processing server 122 is discussed inconnection with FIG. 5 below.

The social network server 124 supports various social networkingfunctions and services and makes these functions and services availableto the messaging server 118. To this end, the social network server 124maintains and accesses an entity graph 308 (as shown in FIG. 3) withinthe database 126. Examples of functions and services supported by thesocial network server 124 include the identification of other users ofthe messaging system 100 with which a particular user has relationshipsor is “following,” and also the identification of other entities andinterests of a particular user.

Returning to the messaging client 104, features and functions of anexternal resource (e.g., a third-party application 109 or applet) aremade available to a user via an interface of the messaging client 104.The messaging client 104 receives a user selection of an option tolaunch or access features of an external resource (e.g., a third-partyresource), such as external apps 109. The external resource may be athird-party application (external apps 109) installed on the clientdevice 102 (e.g., a “native app”), or a small-scale version of thethird-party application (e.g., an “applet”) that is hosted on the clientdevice 102 or remote of the client device 102 (e.g., on third-partyservers 110). The small-scale version of the third-party applicationincludes a subset of features and functions of the third-partyapplication (e.g., the full-scale, native version of the third-partystandalone application) and is implemented using a markup-languagedocument. In one example, the small-scale version of the third-partyapplication (e.g., an “applet”) is a web-based, markup-language versionof the third-party application and is embedded in the messaging client104. In addition to using markup-language documents (e.g., a .*ml file),an applet may incorporate a scripting language (e.g., a . *js file or a.json file) and a style sheet (e.g., a .*ss file).

In response to receiving a user selection of the option to launch oraccess features of the external resource (external app 109), themessaging client 104 determines whether the selected external resourceis a web-based external resource or a locally-installed externalapplication. In some cases, external applications 109 that are locallyinstalled on the client device 102 can be launched independently of andseparately from the messaging client 104, such as by selecting an icon,corresponding to the external application 109, on a home screen of theclient device 102. Small-scale versions of such external applicationscan be launched or accessed via the messaging client 104 and, in someexamples, no or limited portions of the small-scale external applicationcan be accessed outside of the messaging client 104. The small-scaleexternal application can be launched by the messaging client 104receiving, from a external app(s) server 110, a markup-language documentassociated with the small-scale external application and processing sucha document.

In response to determining that the external resource is alocally-installed external application 109, the messaging client 104instructs the client device 102 to launch the external application 109by executing locally-stored code corresponding to the externalapplication 109. In response to determining that the external resourceis a web-based resource, the messaging client 104 communicates with theexternal app(s) servers 110 to obtain a markup-language documentcorresponding to the selected resource. The messaging client 104 thenprocesses the obtained markup-language document to present the web-basedexternal resource within a user interface of the messaging client 104.

The messaging client 104 can notify a user of the client device 102, orother users related to such a user (e.g., “friends”), of activity takingplace in one or more external resources. For example, the messagingclient 104 can provide participants in a conversation (e.g., a chatsession) in the messaging client 104 with notifications relating to thecurrent or recent use of an external resource by one or more members ofa group of users. One or more users can be invited to join in an activeexternal resource or to launch a recently-used but currently inactive(in the group of friends) external resource. The external resource canprovide participants in a conversation, each using a respectivemessaging client messaging clients 104, with the ability to share anitem, status, state, or location in an external resource with one ormore members of a group of users into a chat session. The shared itemmay be an interactive chat card with which members of the chat caninteract, for example, to launch the corresponding external resource,view specific information within the external resource, or take themember of the chat to a specific location or state within the externalresource. Within a given external resource, response messages can besent to users on the messaging client 104. The external resource canselectively include different media items in the responses, based on acurrent context of the external resource.

The messaging client 104 can present a list of the available externalresources (e.g., third-party or external applications 109 or applets) toa user to launch or access a given external resource. This list can bepresented in a context-sensitive menu. For example, the iconsrepresenting different ones of the external application 109 (or applets)can vary based on how the menu is launched by the user (e.g., from aconversation interface or from a non-conversation interface).

System Architecture

FIG. 2 is a block diagram illustrating further details regarding themessaging system 100, according to some examples. Specifically, themessaging system 100 is shown to comprise the messaging client 104 andthe application servers 114. The messaging system 100 embodies a numberof subsystems, which are supported on the client side by the messagingclient 104 and on the sever side by the application servers 114. Thesesubsystems include, for example, an ephemeral timer system 202, acollection management system 204, an augmentation system 208, a mapsystem 210, a game system 212, and an external resource system 220.

The ephemeral timer system 202 is responsible for enforcing thetemporary or time-limited access to content by the messaging client 104and the messaging server 118. The ephemeral tinier system 202incorporates a number of timers that, based on duration and displayparameters associated with a message, or collection of messages (e.g., astory), selectively enable access (e.g., for presentation and display)to messages and associated content via the messaging client 104. Furtherdetails regarding the operation of the ephemeral timer system 202 areprovided below.

The collection management system 204 is responsible for managing sets orcollections of media (e.g., collections of text, image video, and audiodata). A collection of content (e.g., messages, including images, video,text, and audio) may be organized into an “event gallery” or an “eventstory.” Such a collection may be made available for a specified timeperiod, such as the duration of an event to which the content relates.For example, content relating to a music concert may be made availableas a “story” for the duration of that music concert. The collectionmanagement system 204 may also be responsible for publishing an iconthat provides notification of the existence of a particular collectionto the user interface of the messaging client 104.

The collection management system 204 furthermore includes a curationinterface 206 that allows a collection manager to manage and curate aparticular collection of content. For example, the curation interface206 enables an event organizer to curate a collection of contentrelating to a specific event (e.g., delete inappropriate content orredundant messages). Additionally, the collection management system 204employs machine vision (or image recognition technology) and contentrules to automatically curate a content collection. In certain examples,compensation may be paid to a user for the inclusion of user-generatedcontent into a collection. In such cases, the collection managementsystem 204 operates to automatically make payments to such users for theuse of their content.

The augmentation system 208 provides various functions that enable auser to augment (e.g., annotate or otherwise modify or edit) mediacontent associated with a message. For example, the augmentation system208 provides functions related to the generation and publishing of mediaoverlays for messages processed by the messaging system 100. Theaugmentation system 208 operatively supplies a media overlay oraugmentation (e.g., an image filter) to the messaging client 104 basedon a geolocation of the client device 102. In another example, theaugmentation system 208 operatively supplies a media overlay to themessaging client 104 based on other information, such as social networkinformation of the user of the client device 102. A media overlay mayinclude audio and visual content and visual effects. Examples of audioand visual content include pictures, texts, logos, animations, and soundeffects. An example of a visual effect includes color overlaying. Theaudio and visual content or the visual effects can be applied to a mediacontent item (e.g., a photo) at the client device 102. For example, themedia overlay may include text, a graphical element, or image that canbe overlaid on top of a photograph taken by the client device 102. Inanother example, the media overlay includes an identification of alocation overlay (e.g., Venice beach), a name of a live event, or a nameof a merchant overlay (e.g., Beach Coffee House). In another example,the augmentation system 208 uses the geolocation of the client device102 to identify a media overlay that includes the name of a merchant atthe geolocation of the client device 102. The media overlay may includeother indicia associated with the merchant. The media overlays may bestored in the database 126 and accessed through the database server 120.

In sonic examples, the augmentation system 208 provides a user-basedpublication platform that enables users to select a geolocation on a mapand upload content associated with the selected geolocation. The usermay also specify circumstances under which a particular media overlayshould be offered to other users. The augmentation system 208 generatesa media overlay that includes the uploaded content and associates theuploaded content with the selected geolocation.

In other examples, the augmentation system 208 provides a merchant-basedpublication platform that enables merchants to select a particular mediaoverlay associated with a geolocation via a bidding process. Forexample, the augmentation system 208 associates the media overlay of thehighest bidding merchant with a corresponding geolocation for apredefined amount of time. The augmentation system 208 communicates withthe image processing server 122 to automatically select and activate anaugmented reality experience related to an image captured by the clientdevice 102. Once the augmented reality experience is selected as theuser scans images using a camera in the user's environment, one or moreimages, videos, or augmented reality graphical elements are retrievedand presented as an overlay on top of the scanned images. In some cases,the camera is switched to a front-facing view (e.g., the front-facingcamera of the client device 102 is activated in response to activationof a particular augmented reality experience) and the images from thefront-facing camera of the client device 102 start being displayed onthe client device 102 instead of the rear-facing camera of the clientdevice 102. The one or more images, videos, or augmented realitygraphical elements are retrieved and presented as an overlay on top ofthe images that are captured and displayed by the front-facing camera ofthe client device 102.

The map system 210 provides various geographic location functions, andsupports the presentation of map-based media content and messages by themessaging client 104. For example, the map system 210 enables thedisplay of user icons or avatars (e.g., stored in profile data 316) on amap to indicate a current or past location of “friends” of a user, aswell as media content (e.g., collections of messages includingphotographs and videos) generated by such friends, within the context ofa map. For example, a message posted by a user to the messaging system100 from a specific geographic location may be displayed within thecontext of a map at that particular location to “friends” of a specificuser on a map interface of the messaging client 104.A user canfurthermore share his or her location and status information (e.g.,using an appropriate status avatar) with other users of the messagingsystem 100 via the messaging client 104, with this location and statusinformation being similarly displayed within the context of a mapinterface of the messaging client 104 to selected users.

The game system 212 provides various gaming functions within the contextof the messaging client 104. The messaging client 104 provides a gameinterface providing a list of available games (e.g., web-based games orweb-based applications) that can be launched by a user within thecontext of the messaging client 104, and played with other users of themessaging system 100. The messaging system 100 further enables aparticular user to invite other users to participate in the play of aspecific game, by issuing invitations to such other users from themessaging client 104. The messaging client 104 also supports both voiceand text messaging (e.g., chats) within the context of gatneplay,provides a leaderboard for the games, and also supports the provision ofin-game rewards (e.g., coins and items).

The external resource system 220 provides an interface for the messagingclient 104 to communicate with external app(s) servers 110 to launch oraccess external resources. Each external resource (apps) server 110hosts, for example, a markup language (e.g., HTML5) based application orsmall-scale version of an external application (e.g., game, utility,payment, or ride-sharing application that is external to the messagingclient 104). The messaging client 104 may launch a web-based resource(e.g., application) by accessing the HTML5 file from the externalresource (apps) servers 110 associated with the web-based resource. Incertain examples, applications hosted by external resource servers 110are programmed in JavaScript leveraging a Software Development Kit (SDK)provided by the messaging server 118. The SDK includes ApplicationProgramming Interfaces (APIs) with functions that can be called orinvoked by the web-based application. In certain examples, the messagingserver 118 includes a JavaScript library that provides a giventhird-party resource access to certain user data of the messaging client104. HTML5 is used as an example technology for programming games, butapplications and resources programmed based on other technologies can beused.

In order to integrate the functions of the SDK into the web-basedresource, the SDK is downloaded by an external resource (apps) server110 from the messaging server 118 or is otherwise received by theexternal resource (apps) server 110. Once downloaded or received, theSDK is included as part of the application code of a web-based externalresource. The code of the web-based resource can then call or invokecertain functions of the SDK to integrate features of the messagingclient 104 into the web-based resource.

The SDK stored on the messaging server 118 effectively provides thebridge between an external resource (e.g., third-party or externalapplications 109 or applets and the messaging client 104). This providesthe user with a seamless experience of communicating with other users onthe messaging client 104, while also preserving the look and feel of themessaging client 104. To bridge communications between an externalresource and a messaging client 104, in certain examples, the SDKfacilitates communication between external resource servers 110 and themessaging client 104. In certain examples, a Web ViewJavaScriptBridgerunning on a client device 102 establishes two one-way communicationchannels between a external resource and the messaging client 104.Messages are sent between the external resource and the messaging client104 via these communication channels asynchronously. Each SDK functioninvocation is sent as a message and callback. Each SDK function isimplemented by constructing a unique callback identifier and sending amessage with that callback identifier.

By using the SDK, not all information from the messaging client 104 isshared with external resource servers 110. The SDK limits whichinformation is shared based on the needs of the external resource. Incertain examples, each external resource server 110 provides an HTML5file corresponding to the web-based external resource to the messagingserver 118. The messaging server 118 can add a visual representation(such as a box art or other graphic) of the web-based external resourcein the messaging client 104. Once the user selects the visualrepresentation or instructs the messaging client 104 through a GUI ofthe messaging client 104 to access features of the web-based externalresource, the messaging client 104 obtains the HTML5 file andinstantiates the resources necessary to access the features of theweb-based external resource.

The messaging client 104 presents a graphical user interface (e.g., alanding page or title screen) for an external resource. During, before,or after presenting the landing page or title screen, the messagingclient 104 determines whether the launched external resource has beenpreviously authorized to access user data of the messaging client 104.In response to determining that the launched external resource has beenpreviously authorized to access user data of the messaging client 104,the messaging client 104 presents another graphical user interface ofthe external resource that includes functions and features of theexternal resource. In response to determining that the launched externalresource has not been previously authorized to access user data of themessaging client 104, after a threshold period of time (e.g., 3 seconds)of displaying the landing page or title screen of the external resource,the messaging client 104 slides up (e.g., animates a menu as surfacingfrom a bottom of the screen to a middle of or other portion of thescreen) a menu for authorizing the external resource to access the userdata. The menu identifies the type of user data that the externalresource will be authorized to use. In response to receiving a userselection of an accept option, the messaging client 104 adds theexternal resource to a list of authorized external resources and allowsthe external resource to access user data from the messaging client 104.In some examples, the external resource is authorized by the messagingclient 104 to access the user data in accordance with an OAuth 2framework.

The messaging client 104 controls the type of user data that is sharedwith external resources based on the type of external resource beingauthorized. For example, external resources that include full-scaleexternal applications (e.g., a third-party or external application 109)are provided with access to a first type of user data (e.g., onlytwo-dimensional avatars of users with or without different avatarcharacteristics). As another example, external resources that includesmall-scale versions of external applications (e.g., web-based versionsof third-party applications) are provided with access to a second typeof user data (e.g., payment information, two-dimensional avatars ofusers, three-dimensional avatars of users, and avatars with variousavatar characteristics). Avatar characteristics include different waysto customize a look and feel of an avatar, such as different poses,facial features, clothing, and so forth.

The pose generation system 230 generates and implements the CHAIN modelto synthesize the pose of a person with clothes of another and/or tosynthesize the pose of a person in an input image in a different posedepicted in a target image.

Data Architecture

FIG. 3 is a schematic diagram illustrating data structures 300, whichmay be stored in the database 126 of the messaging server system 108,according to certain examples. While the content of the database 126 isshown to comprise a number of tables, it will be appreciated that thedata could be stored in other types of data structures (e.g., as anobject-oriented database).

The database 126 includes message data stored within a message table302. This message data includes, for any particular one message, atleast message sender data, message recipient (or receiver) data, and apayload. Further details regarding information that may be included in amessage, and included within the message data stored in the messagetable 302, is described below with reference to FIG. 4.

An entity table 306 stores entity data, and is linked (e.g.,referentially) to an entity graph 308 and profile data 316. Entities forwhich records are maintained within the entity table 306 may includeindividuals, corporate entities, organizations, objects, places, events,and so forth. Regardless of entity type, any entity regarding which themessaging server system 108 stores data may be a recognized entity. Eachentity is provided with a unique identifier, as well as an entity typeidentifier (not shown).

The entity graph 308 stores information regarding relationships andassociations between entities. Such relationships may be social,professional (e.g., work at a common corporation or organization)interested-based or activity-based, merely for example.

The profile data 316 stores multiple types of profile data about aparticular entity. The profile data 316 may be selectively used andpresented to other users of the messaging system 100, based on privacysettings specified by a particular entity. Where the entity is anindividual, the profile data 316 includes, for example, a user name,telephone number, address, settings (e.g., notification and privacysettings), as well as a user-selected avatar representation (orcollection of such avatar representations). A particular user may thenselectively include one or more of these avatar representations withinthe content of messages communicated via the messaging system 100, andon map interfaces displayed by messaging clients 104 to other users. Thecollection of avatar representations may include “status avatars,” whichpresent a graphical representation of a status or activity that the usermay select to communicate at a particular time.

Where the entity is a group, the profile data 316 for the group maysimilarly include one or more avatar representations associated with thegroup, in addition to the group name, members, and various settings(e.g., notifications) for the relevant group.

The database 126 also stores augmentation data, such as overlays orfilters, in an augmentation table 310. The augmentation data isassociated with and applied to videos (for which data is stored in avideo table 304) and images (for which data is stored in an image table312).

Filters, in one example, are overlays that are displayed as overlaid onan image or video during presentation to a recipient user. Filters maybe of various types, including user-selected filters from a set offilters presented to a sending user by the messaging client 104 when thesending user is composing a message. Other types of filters includegeolocation filters (also known as geo-filters), which may be presentedto a sending user based on geographic location. For example, geolocationfilters specific to a neighborhood or special location may be presentedwithin a user interface by the messaging client 104, based ongeolocation information determined by a Global Positioning System (GPS)unit of the client device 102.

Another type of filter is a data filter, which may be selectivelypresented to a sending user by the messaging client 104, based on otherinputs or information gathered by the client device 102 during themessage creation process. Examples of data filters include currenttemperature at a specific location, a current speed at which a sendinguser is traveling, battery life for a client device 102, or the currenttime.

Other augmentation data that may be stored within the image table 312includes augmented reality content items (e.g., corresponding toapplying lenses or augmented reality experiences). An augmented realitycontent item may be a real-time special effect and sound that may beadded to an image or a video. Each augmented reality experience may beassociated with one or more marker images. In some examples, when amarker image is determined to match a query image received from theclient device 102, the corresponding augmented reality experience (e.g.,the augmentation data) of the maker image is retrieved from the imagetable 312 and provided to the client device 102.

As described above, augmentation data includes augmented reality contentitems, overlays, image transformations, AR images, and similar termsthat refer to modifications that may be applied to image data (e.g.,videos or images). This includes real-time modifications, which modifyan image as it is captured using device sensors (e.g., one or multiplecameras) of a client device 102 and then displayed on a screen of theclient device 102 with the modifications. This also includesmodifications to stored content, such as video clips in a gallery thatmay be modified. For example, in a client device 102 with access tomultiple augmented reality content items, a user can use a single videoclip with multiple augmented reality content items to see how thedifferent augmented reality content items will modify the stored clip.For example, multiple augmented reality content items that applydifferent pseudorandom movement models can be applied to the samecontent by selecting different augmented reality content items for thecontent. Similarly, real-time video capture may be used with anillustrated modification to show how video images currently beingcaptured by sensors of a client device 102 would modify the captureddata. Such data may simply be displayed on the screen and not stored inmemory, or the content captured by the device sensors may be recordedand stored in memory with or without the modifications (or both). Insome systems, a preview feature can show how different augmented realitycontent items will look within different windows in a display at thesame time. This can, for example, enable multiple windows with differentpseudorandom animations to be viewed on a display at the same time.

Data and various systems using augmented reality content items or othersuch transform systems to modify content using this data can thusinvolve detection of objects (e.g., faces, hands, bodies, cats, dogs,surfaces, objects, etc.), tracking of such objects as they leave, enter,and move around the field of view in video frames, and the modificationor transformation of such objects as they are tracked. In variousexamples, different methods for achieving such transformations may beused. Some examples may involve generating a three-dimensional meshmodel of the object or objects, and using transformations and animatedtextures of the model within the video to achieve the transformation. Inother examples, tracking of points on an object may be used to place animage or texture (which may be two dimensional or three dimensional) atthe tracked position. In still further examples, neural network analysisof video frames may be used to place images, models, or textures incontent (e.g., images or frames of video). Augmented reality contentitems thus refer both to the images, models, and textures used to createtransformations in content, as well as to additional modeling andanalysis information needed to achieve such transformations with objectdetection, tracking, and placement.

Real-time video processing can be performed with any kind of video data(e.g., video streams, video files, etc.) saved in a memory of acomputerized system of any kind. For example, a user can load videofiles and save them in a memory of a device, or can generate a videostream using sensors of the device. Additionally, any objects can beprocessed using a computer animation model, such as a human's face andparts of a human body, animals, or non-living things such as chairs,cars, or other objects.

In some examples, when a particular modification is selected along withcontent to be transformed, elements to be transformed are identified bythe computing device, and then detected and tracked if they are presentin the frames of the video. The elements of the object are modifiedaccording to the request for modification, thus transforming the framesof the video stream. Transformation of frames of a video stream can beperformed by different methods for different kinds of transformation.For example, for transformations of frames mostly referring to changingforms of object's elements, characteristic points for each element of anobject are calculated (e.g., using an Active Shape Model (ASM) or otherknown methods). Then, a mesh based on the characteristic points isgenerated for each of the at least one element of the object. This meshis used in the following stage of tracking the elements of the object inthe video stream. In the process of tracking, the mentioned mesh foreach element is aligned with a position of each element. Then,additional points are generated on the mesh. A first set of first pointsis generated for each element based on a request for modification, and aset of second points is generated for each element based on the set offirst points and the request for modification. Then, the frames of thevideo stream can be transformed by modifying the elements of the objecton the basis of the sets of first and second points and the mesh. Insuch method, a background of the modified object can be changed ordistorted as well by tracking and modifying the background.

In some examples, transformations changing some areas of an object usingits elements can be performed by calculating characteristic points foreach element of an object and generating a mesh based on the calculatedcharacteristic points. Points are generated on the mesh, and thenvarious areas based on the points are generated. The elements of theobject are then tracked by aligning the area for each element with aposition for each of the at least one element, and properties of theareas can be modified based on the request for modification, thustransforming the frames of the video stream. Depending on the specificrequest for modification, properties of the mentioned areas can betransformed in different ways. Such modifications may involve changingcolor of areas; removing at least some part of areas from the frames ofthe video stream; including one or more new objects into areas which arebased on a request for modification; and modifying or distorting theelements of an area or object. In various examples, any combination ofsuch modifications or other similar modifications may be used. Forcertain models to be animated, some characteristic points can beselected as control points to be used in determining the entirestate-space of options for the model animation.

In some examples of a computer animation model to transform image datausing face detection, the face is detected on an image with use of aspecific face detection algorithm (e.g., Viola-Jones). Then, an ActiveShape Model (ASM) algorithmis applied to the face region of an image todetect facial feature reference points.

Other methods and algorithms suitable for face detection can be used.For example, in some examples, features are located using a landmark,which represents a distinguishable point present in most of the imagesunder consideration. For facial landmarks, for example, the location ofthe left eye pupil may be used. If an initial landmark is notidentifiable (e.g., if a person has an eyepatch), secondary landmarksmay be used. Such landmark identification procedures may be used for anysuch objects. In some examples, a set of landmarks forms a shape. Shapescan be represented as vectors using the coordinates of the points in theshape. One shape is aligned to another with a similarity transform(allowing translation, scaling, and rotation) that minimizes the averageEuclidean distance between shape points. The mean shape is the mean ofthe aligned training shapes.

In some examples, a search for landmarks from the mean shape aligned tothe position and size of the face determined by a global face detectoris started. Such a search then repeats the steps of suggesting atentative shape by adjusting the locations of shape points by templatematching of the image texture around each point and then conforming thetentative shape to a global shape model until convergence occurs. Insome systems, individual template matches are unreliable, and the shapemodel pools the results of the weak template matches to form a strongeroverall classifier. The entire search is repeated at each level in animage pyramid, from coarse to fine resolution.

A transformation system can capture an image or video stream on a clientdevice (e.g., the client device 102) and perform complex imagemanipulations locally on the client device 102 while maintaining asuitable user experience, computation time, and power consumption. Thecomplex image manipulations may include size and shape changes, emotiontransfers (e.g., changing a face from a frown to a smile), statetransfers (e.g., aging a subject, reducing apparent age, changinggender), style transfers, graphical element application, and any othersuitable image or video manipulation implemented by a convolutionalneural network that has been configured to execute efficiently on theclient device 102.

In some examples, a computer animation model to transform image data canbe used by a system where a user may capture an image or video stream ofthe user (e.g., a selfie) using a client device 102 having a neuralnetwork operating as part of a messaging client 104 operating on theclient device 102. The transformation system operating within themessaging client 104 determines the presence of a face within the imageor video stream and. provides modification icons associated with acomputer animation model to transform image data, or the computeranimation model can be present as associated with an interface describedherein. The modification icons include changes that may be the basis formodifying the user's face within the image or video stream as part ofthe modification operation. Once a modification icon is selected, thetransformation system initiates a process to convert the image of theuser to reflect the selected modification icon (e.g., generate a smilingface on the user). A modified image or video stream may be presented ina graphical user interface displayed on the client device 102 as soon asthe image or video stream is captured, and a specified modification isselected. The transformation system may implement a complexconvolutional neural network on a portion of the image or video streamto generate and apply the selected modification. That is, the user maycapture the image or video stream and be presented with a modifiedresult in real-time or near real-time once a modification icon has beenselected. Further, the modification may be persistent while the videostream is being captured, and the selected modification icon remainstoggled. Machine-taught neural networks may be used to enable suchmodifications.

The graphical user interface, presenting the modification performed bythe transformation system, may supply the user with additionalinteraction options. Such options may be based on the interface used toinitiate the content capture and selection of a particular computeranimation model (e.g., initiation from a content creator userinterface). In various examples, a modification may be persistent afteran initial selection of a modification icon. The user may toggle themodification on or off by tapping or otherwise selecting the face beingmodified by the transformation system and store it for later viewing orbrowse to other areas of the imaging application. Where multiple facesare modified by the transformation system, the user may toggle themodification on or off globally by tapping or selecting a single facemodified and displayed within a graphical user interface. In someexamples, individual faces, among a group of multiple faces, may beindividually modified, or such modifications may be individually toggledby tapping or selecting the individual face or a series of individualfaces displayed within the graphical user interface.

A story table 314 stores data regarding collections of messages andassociated image, video, or audio data, which are compiled into acollection (e.g., a story or a gallery). The creation of a particularcollection may be initiated by a particular user (e.g., each user forwhich a record is maintained in the entity table 306). A user may createa “personal story” in the form of a collection of content that has beencreated and sent/broadcast by that user. To this end, the user interfaceof the messaging client 104 may include an icon that is user-selectableto enable a sending user to add specific content to his or her personalstory.

A collection may also constitute a “live story,” which is a collectionof content from multiple users that is created manually, automatically,or using a combination of manual and automatic techniques. For example,a “live story” may constitute a curated stream of user-submitted contentfrom various locations and events. Users whose client devices havelocation services enabled and are at a common location event at aparticular time may, for example, be presented with an option, via auser interface of the messaging client 104, to contribute content to aparticular live story. The live story may be identified to the user bythe messaging client 104, based on his or her location. The end resultis a “live story” told from a community perspective.

A further type of content collection is known as a “location story,”which enables a user whose client device 102 is located within aspecific geographic location (e.g., on a college or university campus)to contribute to a particular collection. In some examples, acontribution to a location story may require a second degree ofauthentication to verify that the end user belongs to a specificorganization or other entity (e.g., is a student on the universitycampus).

As mentioned above, the video table 304 stores video data that, in oneexample, is associated with messages for which records are maintainedwithin the message table 302. Similarly, the image table 312 storesimage data associated with messages for which message data is stored inthe entity table 306. The entity table 306 may associate variousaugmentations from the augmentation table 310 with various images andvideos stored in the image table 312 and the video table 304.

Data Communications Architecture

FIG. 4 is a schematic diagram illustrating a structure of a message 400,according to some examples, generated by a messaging client 104 forcommunication to a further messaging client 104 or the messaging server118. The content of a particular message 400 is used to populate themessage table 302 stored within the database 126, accessible by themessaging server 118. Similarly, the content of a message 400 is storedin memory as “in-transit” or “in-flight” data of the client device 102or the application servers 114. A message 400 is shown to include thefollowing example components:

-   -   message identifier 402: a unique identifier that identifies the        message 400.    -   message text payload 404: text, to be generated by a user via a        user interface of the client device 102, and that is included in        the message 400.    -   message image payload 406: image data, captured by a camera        component of a client device 102 or retrieved from a memory        component of a client device 102, and that is included in the        message 400. Image data for a sent or received message 400 may        be stored in the image table 312.    -   message video payload 408: video data, captured by a camera        component OF retrieved from a memory component of the client        device 102, and that is included in the message 400. Video data        for a sent or received message 400 may be stored in the video        table 304.    -   message audio payload 410: audio data, captured by a microphone        or retrieved from a memory component of the client device 102,        and that is included in the message 400.    -   message augmentation data 412: augmentation data (e.g., filters,        stickers, or other annotations or enhancements) that represents        augmentations to be applied to message image payload 406,        message video payload 408, or message audio payload 410 of the        message 400. Augmentation data for a sent or received message        400 may be stored in the augmentation table 310.    -   message duration parameter 414: parameter value indicating, in        seconds, the amount of time for which content of the message        (e.g., the message image payload 406, message video payload 408,        message audio payload 410) is to be presented or made accessible        to a user via the messaging client 104.    -   message geolocation parameter 416: geolocation data (e.g.,        latitudinal and longitudinal coordinates) associated with the        content payload of the message. Multiple message geolocation        parameter 416 values may be included in the payload, each of        these parameter values being associated with respect to content        items included in the content (e.g., a specific image within the        message image payload 406, or a specific video in the message        video payload 408).    -   message story identifier 418: identifier values identifying one        or more content collections (e.g., “stories” identified in the        story table 314) with which a particular content item in the        message image payload 406 of the message 400 is associated. For        example, multiple images within the message image payload 406        may each be associated with multiple content collections using        identifier values.    -   message tag 420: each message 400 may be tagged with multiple        tags, each of which is indicative of the subject matter of        content included in the message payload. For example, where a        particular image included in the message image payload 406        depicts an animal (e.g., a lion), a tag value may be included        within the message tag 420 that is indicative of the relevant        animal. Tag values may be generated manually, based on user        input, or may be automatically generated using, for example,        image recognition.    -   message sender identifier 422: an identifier (e.g., a messaging        system identifier, email address, or device identifier)        indicative of a user of the client device 102 on which the        message 400 was generated and from which the message 400 was        sent.    -   message receiver identifier 424: an identifier (e.g., a        messaging system identifier, email address, or device        identifier) indicative of a user of the client device 102 to        which the message 400 is addressed.

The contents (e.g., values) of the various components of message 400 maybe pointers to locations in tables within which content data values arestored. For example, an image value in the message image payload 406 maybe a pointer to (or address of) a location within an image table 312.Similarly, values within the message video payload 408 may point to datastored within a video table 304, values stored within the messageaugmentation data 412 may point to data stored in an augmentation table310, values stored within the message story identifier 418 may point todata stored in a story table 314, and values stored within the messagesender identifier 422 and the message receiver identifier 424 may pointto user records stored within an entity table 306.

FIG. 5 is a diagrammatic representation of the operations 500 performedby a pose generation system 230, in accordance with some examplesSpecifically, the operations 500 represent a manner of training theCHAIN implementation of the pose generation system 230. To train thepose generation system 230, an input image 520 is received which may bea 2D image of a person in a given pose. A target image 510 may includethe same or similar image as the input image 520. A feature extractor550 is applied to the input image 520 to generate a set of soft featurepooling 552. The soft feature pooling 552 may be a matrix of thecollection of features extracted from the input image 520 that arearranged based on expected locations of different joints.

As an example, a first row of the matrix may include a set of featuresthat correspond to the shoulder joints. Features that are close to theexpected location of the shoulder joint are assigned greater weightsthan those further away from the shoulder joint. A surface coordinaterepresentation 530 of the different landmarks or joints is received andused to obtain the features or pixel values of the input image 520 andto assign the features or pixel values on the landmark or joint basis.The surface coordinate representation 530 can be received as atwo-dimensional continuous surface representation of a three-dimensionalobject and comprises a plurality of landmark locations. As an example,an ellipse like area on the top right side of the estimated softintrinsic distances representation 540 corresponds to the top rightjoint in the surface coordinates representation 530 and the shoulderpart of the input image 520 in the image coordinates representation. Aweighted average of the pixel values in that particular area is computedand assigned to one or more rows of the matrix to generate the softfeature pooling 552. So rather than looking at a particular position andassigning that position as the joint, the system computes an average ofa whole area.

The pose generation system 230 uses dense pose analysis to localizeareas in the human body. In those areas, the pose generation system 230averages the features separately per area and this average is used asthe appearance encoding of the image 520. Each tile in the estimatedsoft intrinsic distances 540 (first set of soft membership functions)represents a likelihood that the pixel values or features of the inputimage 520 correspond to a particular joint based on the surfacecoordinates representation 530. In some cases, the features of eachjoint or matrix row are unpooled by replicating an average of thefeatures across the entire image domain to generate soft featureunpooling 554. This creates a dense feature representation of theextracted features using a second set of soft membership functions. Theaverage is guided by an amplitude that is determined by the map of theestimated soft intrinsic distances 540. Effectively a given feature iscopy and pasted everywhere but is scaled down in areas further away fromthe joint. Namely, for appearance conditioning pose generation system230 uses the same P′ soft membership functions to gather the imageinformation into a compact, controllable appearance code, which is thenbroadcast back into the original image coordinates, and concatenated tothe soft membership functions.

In one example, given an RGB image the pose generation system 230obtains its UV charting using DensePose and softly assigns every objectpixel to the control points based on the Euclidean distance betweentheir respective UV values (e.g., encoded features are generated thatrepresent extracted features using the first set of soft membershipfunctions). A channel for background pixels is introduced, obtaining atensor of P′=P+1 soft membership functions, or regions, that roughlypositions every pixel on the human body. This information allows CHAINto modulate the network's behavior in different ways based on theparticular body area corresponding to pixel i.

In some examples, for the gathering stage the pose generation system 230processes the RGB image with a fully convolutional encoder that producesat its topmost layer K=32 feature values for each of the P′ membershipfunctions, having K×P′ channels in total. Each of these channels encodesdifferent region-specific appearance information, e.g. hair color andstyle around faces, or shoe type around the feet. This information iscompressed per region by performing a membership-weighted estimate ofmean and variance per channel:

m _(p) ^(k) =E _(p)[C ^(k,p)], s _(p) ^(k) =E _(p)[(C ^(k,p) −m _(p)^(k))²], k=1, . . . , K, p=1, . . . P,

where i ranges over neuron positions,

${E_{p}\lbrack x\rbrack} = {\frac{1}{\pi_{i}^{p}}{\sum_{i}{\pi_{i}^{p}x_{i}}}}$

indicates expectation with respect to the soft membership function π_(i)^(p) of region p, and C^(k,p)

is the response for the k-th channel of region p. Both feature mean andvariance are encoded since these are commonly used to describe textureproperties.

Gathering this information provides a concise, D=2K×P′-dimensional codeof appearance in terms of feature statistics in the vicinity of a sparseset of control points. These can be interchanged, or faded between theregions of different persons, allowing for controllable image synthesis,e.g. by gradually interpolating between different identities or clothes.This sparse representation is broadcast into a densely-defined signal byrelying again on the soft membership functions. In particular, thesparse code is spread over the area that it is most responsible for:

${M_{i}^{k,p} = {\sum\limits_{p = 1}^{P}{\pi_{i}^{p}m_{p}^{k}}}},{S_{i}^{k,p} = {\sum\limits_{p = 1}^{P}{\pi_{i}^{p}s_{p}^{k}}}}$

Note that π^(p) functions are defined over the whole image domain, whicheffectively ‘smears’ the k-th channel of the p-th region over the partof the image that it occupies, while smoothly blending it with those ofthe neighboring regions. These operations provide the appearanceconditioning signal, and can be understood as implementing asurface-driven image encoding, such as the encoded geometry andappearance 560.

The estimated soft intrinsic distances 540 are concatenated with thesoft feature unpooled features 554 to provide an encoded geometry andappearance representation 560. The encoded geometry and appearancerepresentation 560 is applied to an Adain network 570 to generate anoutput image.

In an example, the feature extractor 550 is implemented as a neuralnetwork (e.g., a convolutional neural network) to generate the softfeature pooling 552. The feature extractor 550 may be trained on a setof training images. For example, a first training image may be receivedand processed by the feature extractor 550. The feature extractor 550generates the soft feature pooling 552 using a surface coordinaterepresentation 530. The soft feature pooling 552 are processed togenerate the soft feature unpooling 554. The same first training imageis also processed as a target image to obtain the estimated softintrinsic distances 540. The encoded geometry and appearance 560 isgenerated and used by the Adam n network 570 to generate an outputimage. The output image is compared with the first training image tocompute a loss. Based on a deviation between the two images and theloss, parameters of the feature extractor 550 are updated and used toprocess a second training image. Once the loss is within a threshold ora stopping criterion is met, the training ends. Namely, during trainingthe same image is used to perform the pooling and unpooling of thefeatures.

FIG. 6 is a diagrammatic representation of the operations 600 performedby a pose generation system 230, in accordance with some examples. Theoperations 600 are performed after the feature extractor 550 is trained.Namely, rather than the same image being input to as the input image andthe target image, a first image depicting a person in a given pose isreceived as the input image. A target image is received that depicts thesame person or a different person in another pose. The trained featureextractor 550 processes the input image to obtain soft feature pooling.The target image is processed to generate target soft intrinsicdistances. The target soft intrinsic distances are concatenated with theunpooled features of the input image to provide the encoded targetgeometry and input appearance. This information is processed by adecoder, such as the Adain network 570 to generate a decoded outputimage.

Namely, the encoder uses two signals to drive the output. As shown inFIG. 6, the input image is processed to encode the appearance of theinput image. For the pooling the source image is used and for theunpooling the target image is used. For example, the pose generationsystem 230 obtains the weighted average of the features in a given area.The pose generation system 230 then takes the average vector and placesthe features of the area on the target image. Namely, the features ofthe input image are smeared according to the features of the targetimage.

In some cases, the feature extractor 550 is further trained based onpaired images depicting persons in different poses. For example, a firsttraining image depicting a person in a first pose is received as theinput image. A second training image depicting the person in a secondpose is received as the target image. That first training image isprocessed by the feature extractor 550 to generate the soft featurepooling which are then unpooled using the features of the secondtraining image. The unpooled features are concatenated with the targetsoft intrinsic distances and processed by the decoder to generate anoutput image. A loss is computed between the generated output image andthe second training image and this loss is used to update parameters ofthe feature extractor 550 and/or the Adain network 570.

In some cases, not all parts of the target image are observed in theinput image. For example, in one image the pose generation system 230observes only the side of the person and in another the pose generationsystem 230 observes only the front of the person. In such cases, a UVvalue of every pixel in the input image is mapped to distinguish thosepixels that are observed from those that are not observed. A diffusionand attention layer 710, shown in FIG. 7, is a trained network, that maybe included as part of the feature extractor 550, that diffuses visibleinformation to the invisible area in cases where features from anunobserved area is used by the feature extractor 550 and/or the Adainnetwork 570.

The objective of this task is to use separate appearance and a posedonors and synthesize a person that has the appearance of the former andthe pose of the latter donor. The Diffusion-and-Attention layer ornetwork 710 imputes the missing feature values for non-observed partsand then combines them with observed ones. In particular the encodedfeatures are updated through a residual branch modulated by an attentionsignal that allows the pose generation system 230 to make strongerchanges to unobserved features and leave fully observed featuresunchanged:

Diffuse: F_(D)=W F₀

Attend: F′=AF _(D)+(1−A)F _(o)

A _(p)=σ(

w_(p) , C

),

where W, w_(p) are parameters that are learned end-to-end, F_(O)indicates the observed encodings, F_(D) is the result of diffusing theinformation across the control points, A is an attention signal thatindicates whether the encoding should be updated or retained, and C is aP-dimensional vector obtained from the normalized-across-regions area ofthe membership functions,

$C_{p} = {\frac{\sum_{i}\pi_{i}^{p}}{\sum_{p}{\sum_{i}\pi_{i}^{p}}}.}$

Through w_(p) each region p can learn its own attention function,allowing e.g. a smaller head region to have a lower threshold forconsidering that it is occluded than a larger torso region. TheDiffusion-and-Attention layer or network 710 is also trained based onpaired training images to learn and update the diffuse and attendparameters (e.g., W, w_(p)) based on back propagation. The attentionsignal A measures whether a pixel was observed or not. The attentionsignal controls whether a diffused feature or the observed featureshould be used. When a feature is visible, that feature or the expectedfeature is used in the feature extractor 550 and when the feature is notvisible the diffused feature is used instead. In some cases, the softfeature pooling labels the features as diffused features or visiblefeatures that are then used in the soft feature unpooling operations.

FIG. 8 is a diagrammatic representation 800 of the position and featurestatistics modeling, in accordance with some examples. In some cases,the feature extractor 550 further implements the position and featurestatistics modeling.

The position and feature statistics modeling collects first andsecond-order moments of a filterbank for a reference dataset (or asingle image), and then synthesizes a new signal that reproduces thesame statistics. Based on whether the new signal is randomlyinitialized, or bound to stay close to some content signal texturesynthesis or style transfer is provided, respectively. Instead ofinfluencing the decoder network based on the style signal, thestatistics of the network features are adapted so that their grammatrices match. This operation is complemented with a decoder thatlearns a mapping from arbitrary network features to the input image. Assuch, any feature-level operation has a direct image counterpart thatcan be efficiently computed.

The disclosed system introduces charting information in efficient,feed-forward systems for style transfer that relies on Gaussian densitymodeling, and subsequent matching (‘coloring’) of feature statistics.This allows the feature extractor 550 to condition synthesis oncontinuous coordinates, and facilitates texture modeling and inpaintingthat respects surface positions.

The whitening and color transform may be implemented by the featureextractor 550 to match the statistics of VGG network features of acontent image to a style image. In particular, denoting by f ^(c),Σ_(ff) ^(c) the empirical feature mean and covariance of the contentsignal c and f ^(s), Σ_(ff) ^(s) for the style signal respectively, thegoal is match the content features statistics to those of the targetsignal. For this, the feature extractor 550 first centers and rotatesthe content features with a whitening transform:

${{\overset{\hat{}}{f}}^{c} = {W^{c}\left( {f^{c} - {\overset{¯}{f}}^{c}} \right)}},{W^{c} = {E_{c}D_{c}^{- \frac{1}{2}}E_{c}^{T}}},$

where E_(c), D_(c) are formed from the eigenvectors and eigenvalues ofΣ_(ff) ^(c)=E_(c)D_(c)E_(c) ^(T). In the second step the featureextractor 550 transforms the features again with a coloring transform:

${{\overset{\hat{}}{f}}^{s} = {W^{s}\left( {{\overset{\hat{}}{f}}^{c} + {\overset{¯}{f}}^{s}} \right)}},{W^{s} = {E_{s}D_{s}^{\frac{1}{2}}E_{s}^{T}}},$

where now Σ_(ff) ^(s)=E_(s)D_(s)E_(s) ^(T). One can easily verify that{circumflex over (f)}^(c) have zero mean and identity covariance, while{circumflex over (f)}^(s) have the mean f ^(s) and covariance Σ_(ff)^(s) of the style signal. This process is efficient, since it onlyrequires two matrix diagonalizations, rather than gradient descent. Byaccounting for the dependence of the texture statistics on position, thefeature extractor 550 can handle non-stationarity of stylization.

A multivariate Gaussian model is employed to capture the dependence ofthe feature activation vector f on continuous position coordinates x.These can be pixel positions or in our case, the chart coordinatesassociated to a given observation. Specifically, the feature extractor550 considers:

$\left( {f,x} \right) \sim {N\left( {\left( {\overset{¯}{f},\overset{¯}{x}} \right),\begin{bmatrix}\sum_{ff} & \sum_{fx} \\\sum_{xf} & \sum_{xx}\end{bmatrix}} \right)}$

The Gaussian mean and covariance matrices of the source and style imageare estimated by accumulating the local second order statistics withinrespective regions. Using this factorization, the spatially-dependentfeature activations can be modeled through the conditional distributionf|x˜N (f(x), Σ_(f|x)), with

f (x)= f +Σ_(fx)Σ_(xx) ⁻¹(x−x )

Σ_(f|x)=Σ_(ff)−Σ_(fx)Σ_(xx) ⁻¹Σ_(xf)

The position-corrected counterparts of the whitening and coloringtransforms can be obtained as follows:

$\begin{matrix}{{{\overset{\hat{}}{f}}^{c} = {W^{c}\left( {f^{c} - {{\overset{¯}{f}}^{c}(x)}} \right)}},{W^{c} = {E_{c}D_{c}^{- \frac{1}{2}}E_{c}^{T}}},{{\overset{\hat{}}{f}}^{s} = {W^{s}\left( {{\overset{\hat{}}{f}}^{c} + {{\overset{¯}{f}}^{s}(x)}} \right)}},{W^{s} = {E_{s}D_{s}^{\frac{1}{2}}E_{s}^{T}}},} & \end{matrix}$

where E_(s)D_(s)E_(s) ^(T)=Σ_(f|x) ^(s) and E_(c)D_(c)E_(c) ^(T)=Σ_(f|x)^(c) use the conditional feature covariance matrices and the centeringtransform depends on the particular feature position x.

In some cases, the 2-D chart coordinates x are maped through a learnableembedding x′=0(x) implemented through a two-layer MLP with 256 hiddenunits and 16 output vectors. The feature extractor 550 uses jointfeature-texture model when modeling appearance in intrinsic, UVcoordinates. There is mirror symmetry around the center vertical axis(capturing the left/right symmetry of appearance) while features shouldbe more correlated in the horizontal rather than the vertical direction(since texture changes more drastically going from trousers/skirts toblouses/shirts). Based on these observations embedding networks minimizethe following objective:

C(ϕ)=E _(x) _(1,) _(x) ₂ [

ϕ(x₁), ϕ(x₂)

−K(x ₁ ,x ₂)

|²]

where K((u ₁ ,v ₁), (u ₂ , v ₂)))=exp(−α(u ₁ −u ₂)²−β(|v ₁−1/2|−|v₂−1/2|)²),

penalizing distances in the (vertical) u axis more than in the(horizontal) v axis, and capturing the symmetry around the center.

As an example, as shown in FIG. 8, an input image 810 is received. Alongthe horizontal axis a first portion of the input image (e.g., theportion in which the torso appears) is replicated across the imagedomain as shown by 820. Namely, pixels of the first portion are mirroredalong the entire image space of that horizontal axis portion, Along thehorizontal axis a second portion of the input image (e.g., the portionin which the legs appear) is replicated across the image domain as shownby 822. Namely, pixels of the second portion are mirrored along theentire image space of that horizontal axis portion. In this way, if agiven texture appears in a target image, that texture will bestatistically modeled and made to appear in the same portion of theoutput image when applied to the input image. This way, for example, ashirt pattern will be visible across different poses of a target andinput image.

FIG. 9 are diagrammatic representations of graphical user interfaces900, in accordance with some examples. As shown in FIG. 9, an inputimage 910 is received and a target image 920 is obtained. The posegeneration system 230 processes the input image 910 to generate poolingfeatures 552. The pose generation system 230 obtains the target softintrinsic distances from the target image 920 and unspools or generatesthe soft feature unpooling of the pooling features 552 using the targetsoft intrinsic distances from the target image 920. This generates theencoded target geometry and input appearance which is provided to theCHAIN decoder to generate the output image 930. As an example, a personin a first pose with their back to the camera is received as the inputimage and the target image may depict the same person in a second pose,such as a side view, with a different article of clothing, such as ashirt. The pose generation system 230 outputs the image 930 in which theperson depicted in the input image 910 in a first pose is depicted inthe pose of the target image 920 and with the article of clothing of theperson in the target image 920.

FIG. 10A is a flowchart illustrating example operations of the messagingclient 104 in performing process 1000, according to examples. Theprocess 1000 may be embodied in computer-readable instructions forexecution by one or more processors such that the operations of theprocess 1000 may be performed in part or in whole by the functionalcomponents of the messaging server system 108; accordingly, the process1000 is described below by way of example with reference thereto.However, in other examples at least some of the operations of theprocess 1000 may be deployed on various other hardware configurations.The operations in the process 1000 can be performed in any order, inparallel, or may be entirely skipped and omitted.

At operation 1001, the image processing server 122 receives atwo-dimensional continuous surface representation of a three-dimensionalobject, the continuous surface comprising a plurality of landmarklocations. For example, the pose generation system 230 receives asurface coordinate representation 530 (FIG. 5).

At operation 1002, the image processing server 122 determines a firstset of soft membership functions based on a relative location of pointsin the two-dimensional continuous surface representation and thelandmark locations. For example, the pose generation system 230 computesthe estimated soft intrinsic distances 540 based on an input denseposeor target image.

At operation 1003, the image processing server 122 receives atwo-dimensional input image, the input image comprising an image of theobject. For example, the pose generation system 230 receives an inputimage 520.

At operation 1004, the image processing server 122 extracts a pluralityof features from the input image using a feature recognition model. Forexample, the pose generation system 230 applies the feature extractor550 to generate the soft feature pooling 552.

At operation 1005, the image processing server 122 generates an encodedfeature representation of the extracted features using the first set ofsoft membership functions. For example, the pose generation system 230generates soft feature pooling 552 using the surface coordinaterepresentation 530.

At operation 1006, the image processing server 122 generates a densefeature representation of the extracted features from the encodedrepresentation using a second set of soft membership functions. Forexample, the pose generation system 230 performs soft feature unpooling554 using the features of the input densepose or target image (e.g., theestimated soft intrinsic distances 540).

At operation 1007, the image processing server 122 processes the secondset of soft membership functions and dense feature representation usinga neural image decoder model to generate an output image. For example,the pose generation system 230 uses the Adain decoder 570 to process theencoded geometry and appearance 560 information to generate an outputimage.

FIG. 10B is a flowchart illustrating example operations of the messagingclient 104 in performing process 1000, according to examples. Theprocess 1000 may be embodied in computer-readable instructions forexecution by one or more processors such that the operations of theprocess 1000 may be performed in part or in whole by the functionalcomponents of the messaging server system 108; accordingly, the process1000 is described below by way of example with reference thereto.However, in other examples at least some of the operations of theprocess 1000 may be deployed on various other hardware configurations.The operations in the process 1000 can be performed in any order, inparallel, or may be entirely skipped and omitted.

At operation 1011, the image processing server 122 determines a set ofcontent features from a source image using an encoder neural network.For example, the pose generation system 230 processes an input image togenerate a set of features, such as soft feature pooling 552.

At operation 1012, the image processing server 122 determines a set ofstyle features from a style image using the encoder neural network. Forexample, the pose generation system 230 processes a target image toidentify style features (e.g., a pattern on a shirt or pants of theimage).

At operation 1013, the image processing server 122 determines positiondependent content features using joint statistics of position andcontent features in regions of the source image. For example, the posegeneration system 230 identifies regions of the source image throughwhich style features should be replicated, such as a torso region shouldhave features horizontally replicated but not vertically replicated. Asanother example, a head region is a position dependent content featurethat should not have a style applied to it.

At operation 1014, the image processing server 122 determines positiondependent style features using joint statistics of position and stylefeatures in regions of the style image. For example, the pose generationsystem 230 identifies regions of the source image through which stylefeatures should be replicated, such as a torso region should havefeatures horizontally replicated but not vertically replicated.Specifically, each region 820 and 822 replicates the features of thestyle image 810 horizontally across its region.

At operation 1015, the image processing server 122 generates a set oftransformed content features from the set of position dependent contentfeatures based on the joint statistics of position and content features.

At operation 1016, the image processing server 122 generates a set oftransformed style features from the set of transformed content featuresbased on the joint statistics of position and style features. Forexample, the pose generation system 230 applies the style of the styleimage in one region (e.g., the shirt region) but not another (e.g., thehead region) to the source image.

At operation 1017, the image processing server 122 generates anotheroutput image from the transformed set of style features and thetransformed set of content features using a decoder neural network.

Machine Architecture

FIG. 11 is a diagrammatic representation of the machine 1100 withinwhich instructions 1108 (e.g., software, a program, an application, anapplet, an app, or other executable code) for causing the machine 1100to perform any one or more of the methodologies discussed herein may beexecuted. For example, the instructions 1108 may cause the machine 1100to execute any one or more of the methods described herein. Theinstructions 1108 transform the general, non-programmed machine 1100into a particular machine 1100 programmed to carry out the described andillustrated functions in the manner described. The machine 1100 mayoperate as a standalone device or may be coupled (e.g., networked) toother machines. In a networked deployment, the machine 1100 may operatein the capacity of a server machine or a client machine in aserver-client network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. The machine 1100 maycomprise, but not be limited to, a server computer, a client computer, apersonal computer (PC), a tablet computer, a laptop computer, a netbook,a set-top box (STB), a personal digital assistant (PDA), anentertainment media system, a cellular telephone, a smartphone, a mobiledevice, a wearable device (e.g., a smartwatch), a smart home device(e.g., a smart appliance), other smart devices, a web appliance, anetwork router, a network switch, a network bridge, or any machinecapable of executing the instructions 1108, sequentially or otherwise,that specify actions to be taken by the machine 1100. Further, whileonly a single machine 1100 is illustrated, the term “machine” shall alsobe taken to include a collection of machines that individually orjointly execute the instructions 1108 to perform any one or more of themethodologies discussed herein. The machine 1100, for example, maycomprise the client device 102 or any one of a number of server devicesforming part of the messaging server system 108. In some examples, themachine 1100 may also comprise both client and server systems, withcertain operations of a particular method or algorithm being performedon the server-side and with certain operations of the particular methodor algorithm being performed on the client-side.

The machine 1100 may include processors 1102, memory 1104, andinput/output (I/O) components 1138, which may be configured tocommunicate with each other via a bus 1140. In an example, theprocessors 1102 (e.g., a Central Processing Unit (CPU), a ReducedInstruction Set Computing (RISC) Processor, a Complex Instruction SetComputing (CISC) Processor, a Graphics Processing Unit (GPU), a DigitalSignal Processor (DSP), an Application Specific Integrated Circuit(ASIC), a Radio-Frequency Integrated Circuit (RFIC), another processor,or any suitable combination thereof) may include, for example, aprocessor 1106 and a processor 1110 that execute the instructions 1108.The term “processor” is intended to include multi-core processors thatmay comprise two or more independent processors (sometimes referred toas “cores”) that may execute instructions contemporaneously. AlthoughFIG. 11 shows multiple processors 1102, the machine 1100 may include asingle processor with a single-core, a single processor with multiplecores (e.g., a multi-core processor), multiple processors with a singlecore, multiple processors with multiples cores, or any combinationthereof.

The memory 1104 includes a main memory 1112, a static memory 1114, and astorage unit 1116, all accessible to the processors 1102 via the bus1140 The main memory 1104, the static memory 1114, and the storage unit1116 store the instructions 1108 embodying any one or more of themethodologies or functions described herein. The instructions 1108 mayalso reside, completely or partially, within the main memory 1112,within the static memory 1114, within machine-readable medium 1118within the storage unit 1116, within at least one of the processors 1102(e.g., within the processor's cache memory), or any suitable combinationthereof, during execution thereof by the machine 1100.

The I/O components 1138 may include a wide variety of components toreceive input, provide output, produce output, transmit information,exchange information, capture measurements, and so on. The specific I/Ocomponents 1138 that are included in a particular machine will depend onthe type of machine. For example, portable machines such as mobilephones may include a touch input device or other such input mechanisms,while a headless server machine will likely not include such a touchinput device. It will be appreciated that the I/O components 1138 mayinclude many other components that are not shown in FIG. 11. In variousexamples, the I/O components 1138 may include user output components1124 and user input components 1126. The user output components 1124 mayinclude visual components (e.g., a display such as a plasma displaypanel (PDP), a light-emitting diode (LED) display, a liquid crystaldisplay (LCD), a projector, or a cathode ray tube (CRT)), acousticcomponents (e.g., speakers), haptic components (e.g., a vibratory motor,resistance mechanisms), other signal generators, and so forth. The userinput components 1126 may include alphanumeric input components (e.g., akeyboard, a touch screen configured to receive alphanumeric input, aphoto-optical keyboard, or other alphanumeric input components),point-based input components (e.g., a mouse, a touchpad, a trackball, ajoystick, a motion sensor, or another pointing instrument), tactileinput components (e.g., a physical button, a touch screen that provideslocation and force of touches or touch gestures, or other tactile inputcomponents), audio input components (e.g., a microphone), and the like.

In further examples, the I/O components 1138 may include biometriccomponents 1128, motion components 1130, environmental components 1132,or position components 1134, among a wide array of other components. Forexample, the biometric components 1128 include components to detectexpressions (e.g., hand expressions, facial expressions, vocalexpressions, body gestures, or eye-tracking), measure biosignals (e.g.,blood pressure, heart rate, body temperature, perspiration, or brainwaves), identify a person (e.g., voice identification, retinalidentification, facial identification, fingerprint identification, orelectroencephalogram-based identification), and the like. The motioncomponents 1130 include acceleration sensor components (e.g.,accelerometer), gravitation sensor components, rotation sensorcomponents (e.g., gyroscope).

The environmental components 1132 include, for example, one or cameras(with still image/photograph and video capabilities), illuminationsensor components (e.g., photometer), temperature sensor components(e.g., one or more thermometers that detect ambient temperature),humidity sensor components, pressure sensor components (e.g.,barometer), acoustic sensor components (e.g., one or more microphonesthat detect background noise), proximity sensor components (e.g.,infrared sensors that detect nearby objects), gas sensors (e.g., gasdetection sensors to detection concentrations of hazardous gases forsafety or to measure pollutants in the atmosphere), or other componentsthat may provide indications, measurements, or signals corresponding toa surrounding physical environment.

With respect to cameras, the client device 102 may have a camera systemcomprising, for example, front cameras on a front surface of the clientdevice 102 and rear cameras on a rear surface of the client device 102.The front cameras may, for example, be used to capture still images andvideo of a user of the client device 102 (e.g., “selfies”), which maythen be augmented with augmentation data (e.g., filters) describedabove. The rear cameras may, for example, be used to capture stillimages and videos in a more traditional camera mode, with these imagessimilarly being augmented with augmentation data. In addition to frontand rear cameras, the client device 102 may also include a 360° camerafor capturing 360° photographs and videos.

Further, the camera system of a client device 102 may include dual rearcameras (e.g., a primary camera as well as a depth-sensing camera), oreven triple, quad or penta rear camera configurations on the front andrear sides of the client device 102. These multiple cameras systems mayinclude a wide camera, an ultra-wide camera, a telephoto camera, a macrocamera, and a depth sensor, for example.

The position components 1134 include location sensor components (e.g., aGPS receiver component), altitude sensor components (e.g., altimeters orbarometers that detect air pressure from which altitude may be derived),orientation sensor components (e.g., magnetometers), and the like.

Communication may be implemented using a wide variety of technologies.The I/O components 1138 further include communication components 1136operable to couple the machine 1100 to a network 1120 or devices 1122via respective coupling or connections. For example, the communicationcomponents 1136 may include a network interface component or anothersuitable device to interface with the network 1120. In further examples,the communication components 1136 may include wired communicationcomponents, wireless communication components, cellular communicationcomponents, Near Field Communication (NFC) components, Bluetooth®components (e.g., Bluetooth®Low Energy), Wi-Fi® components, and othercommunication components to provide communication via other modalities.The devices 1122 may be another machine or any of a wide variety ofperipheral devices (e.g., a peripheral device coupled via a USB),

Moreover, the communication components 1136 may detect identifiers orinclude components operable to detect identifiers. For example, thecommunication components 1136 may include Radio Frequency Identification(RFID) tag reader components, NFC smart tag detection components,optical reader components (e.g., an optical sensor to detectone-dimensional bar codes such as Universal Product Code (UPC) bar code,multi-dimensional bar codes such as Quick Response (QR) code, Azteccode, Data Matrix, Dataglyph, MaxiCode, PDF417, Ultra Code, UCC RSS-2Dbar code, and other optical codes), or acoustic detection components(e.g., microphones to identify tagged audio signals). In addition, avariety of information may be derived via the communication components1136, such as location via Internet Protocol (IP) geolocation, locationvia Wi-Fi® signal triangulation, location via detecting an NFC beaconsignal that may indicate a particular location, and so forth.

The various memories (e.g., main memory 1112, static memory 1114, andmemory of the processors 1102) and storage unit 1116 may store one ormore sets of instructions and data structures (e.g., software) embodyingor used by any one or more of the methodologies or functions describedherein. These instructions the instructions 1108), when executed byprocessors 1102, cause various operations to implement the disclosedexamples.

The instructions 1108 may be transmitted or received over the network1120, using a transmission medium, via a network interface device (e.g.,a network interface component included in the communication components1136) and using any one of several well-known transfer protocols (e.g.,hypertext transfer protocol (HTTP)). Similarly, the instructions 1108may be transmitted or received using a transmission medium via acoupling (e.g., a peer-to-peer coupling) to the devices 1122.

Software Architecture

FIG. 12 is a block diagram 1200 illustrating a software architecture1204, which can be installed on any one or more of the devices describedherein. The software architecture 1204 is supported by hardware such asa machine 1202 that includes processors 1220, memory 1226, and I/Ocomponents 1238. In this example, the software architecture 1204 can beconceptualized as a stack of layers, where each layer provides aparticular functionality. The software architecture 1204 includes layerssuch as an operating system 1212, libraries 1210, frameworks 1208, andapplications 1206. Operationally, the applications 1206 invoke API calls1250 through the software stack and receive messages 1252 in response tothe API calls 1250.

The operating system 1212 manages hardware resources and provides commonservices. The operating system 1212 includes, for example, a kernel1214, services 1216, and drivers 1222. The kernel 1214 acts as anabstraction layer between the hardware and the other software layers.For example, the kernel 1214 provides memory management, processormanagement (e.g., scheduling), component management, networking, andsecurity settings, among other functionality. The services 1216 canprovide other common services for the other software layers. The drivers1222 are responsible for controlling or interfacing with the underlyinghardware. For instance, the drivers 1222 can include display drivers,camera drivers, BLUETOOTH® or BLUETOOTH® Low Energy drivers, flashmemory drivers, serial communication drivers (e.g., USB drivers), WI-FI®drivers, audio drivers, power management drivers, and so forth.

The libraries 1210 provide a common low-level infrastructure used by theapplications 1206. The libraries 1210 can include system libraries 1218(e.g., C standard library) that provide functions such as memoryallocation functions, string manipulation functions, mathematicfunctions, and the like. In addition, the libraries 1210 can include APIlibraries 1224 such as media libraries (e.g., libraries to supportpresentation and manipulation of various media formats such as MovingPicture Experts Group-4 (MPEG4), Advanced Video Coding (H.264 or AVC),Moving Picture Experts Group Layer-3 (MP3), Advanced Audio Coding (AAC),Adaptive Multi-Rate (AMR) audio codec, Joint Photographic Experts Group(JPEG or JPG), or Portable Network Graphics (PNG)), graphics libraries(e.g., an OpenGL framework used to render in two dimensions (2D) andthree dimensions (3D) in a graphic content on a display), databaselibraries (e.g., SQLite to provide various relational databasefunctions), web libraries (e.g., WebKit to provide web browsingfunctionality), and the like. The libraries 1210 can also include a widevariety of other libraries 1228 to provide many other APIs to theapplications 1206.

The frameworks 1208 provide a common high-level infrastructure that isused by the applications 1206. For example, the frameworks 1208 providevarious graphical user interface (GUI) functions, high-level resourcemanagement, and high-level location services. The frameworks 1208 canprovide a broad spectrum of other APIs that can be used by theapplications 1206, some of which may be specific to a particularoperating system or platform.

In an example, the applications 1206 may include a home application1236, a contacts application 1230, a browser application 1232, a bookreader application 1234, a location application 1242, a mediaapplication 1244, a messaging application 1246, a game application 1248,and a broad assortment of other applications such as a externalapplication 1240. The applications 1206 are programs that executefunctions defined in the programs. Various programming languages can beemployed to create one or more of the applications 1206, structured in avariety of manners, such as object-oriented programming languages (e.g.,Objective-C, Java, or C++) or procedural programming languages (e.g., Cor assembly language). In a specific example, the external application1240 (e.g., an application developed using the ANDROID™ or IOS™ softwaredevelopment kit (SDK) by an entity other than the vendor of theparticular platform) may be mobile software running on a mobileoperating system such as IOS™, ANDROID™, WINDOWS® Phone, or anothermobile operating system. In this example, the external application 1240can invoke the API calls 1250 provided b the operating system 1212 tofacilitate functionality described herein.

Glossary

“Carrier signal” refers to any intangible medium that is capable ofstoring, encoding, or carrying instructions for execution by themachine, and includes digital or analog communications signals or otherintangible media to facilitate communication of such instructions.Instructions may be transmitted or received over a network using atransmission medium via a network interface device.

“Client device” refers to any machine that interfaces to acommunications network to obtain resources from one or more serversystems or other client devices. A client device may be, but is notlimited to, a mobile phone, desktop computer, laptop, portable digitalassistants (PDAs), smartphones, tablets, ultrabooks, netbooks, laptops,multi-processor systems, microprocessor-based or programmable consumerelectronics, game consoles, set-top boxes, or any other communicationdevice that a user may use to access a network.

“Communication network” refers to one or more portions of a network thatmay be an ad hoc network, an intranet, an extranet, a virtual privatenetwork (VPN), a local area network (LAN), a wireless LAN (WLAN), a widearea network (WAN), a wireless WAN (WWAN), a metropolitan area network(MAN), the Internet, a portion of the Internet, a portion of the PublicSwitched Telephone Network (PSTN), a plain old telephone service (POTS)network, a cellular telephone network, a wireless network, a Wi-Fi®network, another type of network, or a combination of two or more suchnetworks. For example, a network or a portion of a network may include awireless or cellular network and the coupling may be a Code DivisionMultiple Access (CDMA) connection, a Global System for Mobilecommunications (GSM) connection, or other types of cellular or wirelesscoupling. In this example, the coupling may implement any of a varietyof types of data transfer technology, such as Single Carrier RadioTransmission Technology (1×RTT), Evolution-Data Optimized (EVDO)technology, General Packet Radio Service (GPRS) technology, EnhancedData rates for GSM Evolution (EDGE) technology, third GenerationPartnership Project (3GPP) including 3G, fourth generation wireless (4G)networks, Universal Mobile Telecommunications System (UMTS), High SpeedPacket Access (HSPA), Worldwide Interoperability for Microwave Access(WiMAX), Long Term Evolution (LTE) standard, others defined by variousstandard-setting organizations, other long-range protocols, or otherdata transfer technology.

“Component” refers to a device, physical entity, or logic havingboundaries defined by function or subroutine calls, branch points, APIs,or other technologies that provide for the partitioning ormodularization of particular processing or control functions. Componentsmay be combined via their interfaces with other components to carry outa machine process. A component may be a packaged functional hardwareunit designed for use with other components and a part of a program thatusually performs a particular function of related functions.

Components may constitute either software components (e.g., codeembodied on a machine-readable medium) or hardware components. A.“hardware component” is a tangible unit capable of performing certainoperations and may be configured or arranged in a certain physicalmanner. In various examples, one or more computer systems (e.g., astandalone computer system, a client computer system, or a servercomputer system) or one or more hardware components of a computer system(e.g., a processor or a group of processors) may be configured bysoftware (e.g., an application or application portion) as a hardwarecomponent that operates to perform certain operations as describedherein.

A hardware component may also be implemented mechanically,electronically, or any suitable combination thereof. For example, ahardware component may include dedicated circuitry or logic that ispermanently configured to perform certain operations. A hardwarecomponent may be a special-purpose processor, such as afield-programmable gate array (FPGA) or an application specificintegrated circuit (ASIC), A hardware component may also includeprogrammable logic or circuitry that is temporarily configured bysoftware to perform certain operations. For example, a hardwarecomponent may include software executed by a general-purpose processoror other programmable processor. Once configured by such software,hardware components become specific machines (or specific components ofa machine) uniquely tailored to perform the configured functions and areno longer general-purpose processors. It will be appreciated that thedecision to implement a hardware component mechanically, in dedicatedand permanently configured circuitry, or in temporarily configuredcircuitry (e.g., configured by software), may be driven by cost and timeconsiderations. Accordingly, the phrase “hardware component”(or“hardware-implemented component”) should be understood to encompass atangible entity, be that an entity that is physically constructed,permanently configured (e.g., hardwired), or temporarily configured(e.g., programmed) to operate in a certain manner or to perform certainoperations described herein.

Considering examples in which hardware components are temporarilyconfigured (e.g., programmed), each of the hardware components need notbe configured or instantiated at any one instance in time. For example,where a hardware component comprises a general-purpose processorconfigured by software to become a special-purpose processor, thegeneral-purpose processor may be configured as respectively differentspecial-purpose processors (e.g., comprising different hardwarecomponents) at different times. Software accordingly configures aparticular processor or processors, for example, to constitute aparticular hardware component at one instance of time and to constitutea different hardware component at a different instance of time.

Hardware components can provide information to, and receive informationfrom, other hardware components. Accordingly, the described hardwarecomponents may be regarded as being communicatively coupled. Wheremultiple hardware components exist contemporaneously, communications maybe achieved through signal transmission (e.g., over appropriate circuitsand buses) between or among two or more of the hardware components. Inexamples in which multiple hardware components are configured orinstantiated at different times, communications between such hardwarecomponents may be achieved, for example, through the storage andretrieval of information in memory structures to which the multiplehardware components have access. For example, one hardware component mayperform an operation and store the output of that operation in a memorydevice to which it is communicatively coupled. A further hardwarecomponent may then, at a later time, access the memory device toretrieve and process the stored output. Hardware components may alsoinitiate communications with input or output devices, and can operate ona resource (e.g., a collection of information).

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implementedcomponents that operate to perform one or more operations or functionsdescribed herein. As used herein, “processor-implemented component”refers to a hardware component implemented using one or more processors.Similarly, the methods described herein may be at least partiallyprocessor-implemented, with a particular processor or processors beingan example of hardware. For example, at least some of the operations ofa method may be performed by one or more processors 1102 orprocessor-implemented components. Moreover, the one or more processorsmay also operate to support performance of the relevant operations in a“cloud computing” environment or as a “software as a service” (SaaS).For example, at least some of the operations may be performed by a groupof computers (as examples of machines including processors), with theseoperations being accessible via a network (e.g., the Internet) and viaone or more appropriate interfaces (e.g., an API). The performance ofcertain of the operations may be distributed among the processors, notonly residing within a single machine, but deployed across a number ofmachines. In some examples, the processors or processor-implementedcomponents may be located in a single geographic location (e.g., withina home environment, an office environment, or a server farm). In otherexamples, the processors or processor-implemented components may bedistributed across a number of geographic locations.

“Computer-readable storage medium” refers to both machine-storage mediaand transmission media. Thus, the terms include both storagedevices/media and carrier waves/modulated data signals. The terms“machine-readable medium,” “computer-readable medium” and“device-readable medium” mean the same thing and may be usedinterchangeably in this disclosure.

“Ephemeral message” refers to a message that is accessible for atime-limited duration. An ephemeral message may be a text, an image, avideo and the like. The access time for the ephemeral message may be setby the message sender. Alternatively, the access time may be a defaultsetting or a setting specified by the recipient. Regardless of thesetting technique, the message is transitory.

“Machine storage medium” refers to a single or multiple storage devicesand media (e.g., a centralized or distributed database, and associatedcaches and servers) that store executable instructions, routines anddata. The term shall accordingly be taken to include, but not be limitedto, solid-state memories, and optical and magnetic media, includingmemory internal or external to processors. Specific examples ofmachine-storage media, computer-storage media and device-storage mediainclude non-volatile memory, including by way of example semiconductormemory devices, e.g., erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), FPGA, andflash memory devices; magnetic disks such as internal hard disks andremovable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks Theterms “machine-storage medium,” “device-storage medium,”“computer-storage medium” mean the same thing and may be usedinterchangeably in this disclosure. The terms “machine-storage media,”“computer-storage media,” and “device-storage media” specificallyexclude carrier waves, modulated data signals, and other such media, atleast some of which are covered under the term “signal medium.”

“Non-transitory computer-readable storage medium” refers to a tangiblemedium that is capable of storing, encoding, or carrying theinstructions for execution by a machine.

“Signal medium” refers to any intangible medium that is capable ofstoring, encoding, or carrying the instructions for execution by amachine and includes digital or analog communications signals or otherintangible media to facilitate communication of software or data. Theterm “signal medium” shall be taken to include any form of a modulateddata signal, carrier wave, and so forth. The term “modulated datasignal” means a signal that has one or more of its characteristics setor changed in such a matter as to encode information in the signal. Theterms “transmission medium” and “signal medium” mean the same thing andmay be used interchangeably in this disclosure.

Changes and modifications may be made to the disclosed examples withoutdeparting from the scope of the present disclosure. These and otherchanges or modifications are intended to be included within the scope ofthe present disclosure, as expressed in the following claims.

What is claimed is:
 1. A method comprising: receiving a two-dimensional(2D) input age depicting a person in a first pose; receiving a targetimage corresponding to a second pose; processing the 2D input image togenerate soft feature pooling features; processing the target image togenerate target soft intrinsic distances; and decoding features of the2D input image based on a combination of the soft feature poolingfeatures and target soft intrinsic distances to generate a decoded imagethat depicts the person in the second pose.
 2. The method of claim 1,further comprising: determining a first set of soft membership functionsby: determining distances between a plurality of points in atwo-dimensional continuous surface representation and landmark locationsof the 2D input image; and assigning each point in the plurality ofpoints to a landmark based on the determined distances.
 3. The method ofclaim 1, further comprising determining landmark locations using alandmark recognition model.
 4. The method of claim 1, further comprisingdecoding the features by a neural image decoder model comprising aconvolutional neural network conditioned on a two-dimensional continuoussurface representation of the 2D input image.
 5. The method of claim 1,further comprising generating an encoded feature representation ofextracted features of the 2D input image using a first set of softmembership functions by performing a membership-weighted estimate of amean and variance for each channel of the extracted features.
 6. Themethod of claim 5, further comprising: generating a dense featurerepresentation of the extracted features from the encoded featurerepresentation using a second set of soft membership functions byapplying a dual operation to the membership-weighted estimate of a meanand variance for each channel of the extracted features.
 7. The methodof claim 1, further comprising detecting landmarks comprising joints ofthe person.
 8. The method of claim 1, wherein a first set of softmembership functions and a second set of soft membership functions usedto decode the features are the same.
 9. The method of claim 8, furthercomprising: generating a three-dimensional (3D) model of the person fromthe 2D input image; and generating a 2D continuous surfacerepresentation from the 3D model.
 10. The method of any of claim 9,further comprising modifying values in an encoded representation of the2D input image prior to generating a dense feature representation of the2D input image.
 11. The method of claim 1, further comprising:generating a 2D continuous surface representation of a three-dimensional(3D) object from the 2D input image; receiving a further 2D input image,the further input image comprising a further object; generating afurther 2D continuous surface representation of the 3D object from thefurther 2D input image, the further continuous surface comprising aplurality of landmark locations; and determining a second set of softmembership functions based on relative locations of points in thefurther 2D continuous surface representation and the landmark locations.12. The method of claim 11, wherein the decoded image comprises portionscorresponding to unseen portions of the 2D input image and furthercomprising: generating portions of a two-dimensional continuous surfacerepresentation corresponding to the unseen portions from an encodedrepresentation using a learned attention mechanism.
 13. The method ofclaim 12, wherein the learned attention mechanism is based on a firstset of soft membership functions.
 14. The method of claim 1, furthercomprising: determining a set of content features from a source imageusing an encoder neural network; determining a set of style featuresfrom a style image using the encoder neural network; determiningposition dependent content features using joint statistics of positionand content features in regions of the source image; determiningposition dependent style features using joint statistics of position andstyle features in regions of the style image; generating a set oftransformed content features from the set of position. dependent contentfeatures based on the joint statistics of position and content features;generating a set of transformed style features from the set oftransformed content features based on the joint statistics of positionand style features; and generating an output image from the transformedset of style features and the transformed set of content features usinga decoder neural network.
 15. The method of claim 14, further comprisingcombining the output image with another output image to generate acombined image.
 16. The method of claim 14, wherein the joint statisticsof position and content features comprise a content feature mean, acontent position mean and covariances between content features andcontent positions, and wherein determining position dependent contentfeatures comprises determining a conditional model of the contentfeatures conditioned on position.
 17. The method of claim 16, whereinthe conditional model of the content features comprises a positiondependent content mean and a conditional content covariance.
 18. Themethod of claim 17, wherein generating the set of transformed contentfeatures from the set of position dependent content features comprises:centering the position dependent content features based on the positiondependent content mean; and applying a whitening transformation based onthe conditional content covariance.
 19. A system for neural imageanalysis, comprising: a processor configured to perform operationscomprising: receiving a two-dimensional (2D) input image depicting aperson in a first pose; receiving a target image corresponding to asecond pose; processing the 2D input image to generate soft featurepooling features; processing the target image to generate target softintrinsic distances; and decoding features of the 2D input image basedon a combination of the soft feature pooling features and target softintrinsic distances to generate a decoded image that depicts the personin the second pose.
 20. A non-transitory machine-readable storage mediumthat includes instructions that, when executed by one or more processorsof a machine, cause the machine to perform operations for neural imageanalysis comprising: receiving a two-dimensional (2D) input imagedepicting a person in a first pose; receiving a target imagecorresponding to a second pose; processing the 2D input image togenerate soft feature pooling features; processing the target image togenerate target soft intrinsic distances; and decoding features of the2D input image based on a combination of the soft feature poolingfeatures and target soft intrinsic distances to generate a decoded imagethat depicts the person in the second pose.